Revolving-hook sewing-machine.



R. K. HOHMANN. REVOLVING HOOK SEWING MACHINE.

APPLICATION FILED MAY 5,'1913A Patented Mar. 24, 1914 4 SHEETS-SHEET 1".

vlllw" lmiileullll Il" R. K. HOHMANN. RBVOLVING HOOK SEWINGMAGHINE.APPLICATION FILED MAY 5, 191.3. LOQLOGQ.

` Patented Mar. 24, 1914 4 SHEETS-SHEET 2.

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R. K. HOHMANN. RBVOLVING HOOK SEWING MACHINE.

APPLICATIOI FILED MAY5,1913.

Patented Mar. 24,1914;

4 SHEETS-SHEET 3.

R', K. HORMANN. REVOLVING HOOK SEWING MACHINE.

APPLIGATION FILED MAY 5; 1913.

Patented Mar. 24, 1914.

4 SHEETS-SHEET 4.

n sATns PATENT onFIon.

RICHARD-Ie Hermann, or ennvinnnn, ILLINOIS, Assrenon To NATIONAL SEWINGMAcHinn conserva; or .BnLvInnnn, ILLINOIS, A conronArIoN or ILLINOIS.

entremise-facon,sewers-MACHINE.

Leeinee. f han@ Patented llfar. 24, 1914il To all whom it may concern.'4 Be it known that l, RIQHARD A MANN, a citizen of the .United States,and

resident of Belvidere, county of l leone and State of Illinois,haveinvented certain new and useful Improvements vin Revolving-HochSewing-llachines, of' which following' is a specification.

This invention relatesto sewing machines of the revolving hook typeandhas particular reference to the means for retalning the bobbin holderagainst rotation while permitting a loop of thread to pass freely aroundit. f t

The novel features of the invention will be apparent from the ollowindescription, taken in connection with the rawmgs.

In the drawings, Figure 1 is an end view of a machine showing myinvention applied thereto; Fig. 2 is a detail viewfo the spool holderwith the operating means 1n a different positiong. Fig. .-3 1s alongitudinal section through a machine embodying the invention; Fig. f1is a bottomplan view; and Fig. 5 is a vertical section on the line 5-5of Fig. 3. x

rlhe particular machine to which I have shown my' invention applied isof, the commercial type and some of the features of this machine arecoveredby other applications which I am filing herewith.

The machine includes a base 1 carrying a rotary shaft 2 which o cratesthe revolving hook ring 3. An upright hollow standard el carries theIfshaftl 5 driven from the drive shaft 6 in the hollow'liorizontal arm 7.The drive shaft' operates the needle bar 8 carried in the head 9 of themachine and the shaft 6 is driven in any suitable way through the pulley10. The shaft 5 has a bevel gear 11 0n its lower end meshing with abevel gear on the end, of the shaft 2 whereby the shaft 2 will make tworevolutions for each revolution of the shaft 5, and by this means itwill be observed that the revolving hook makes two revolutions each timethe needle reciprocates. They rotary hook is arranged below the elevatedcloth plate 12, and thaty cloth plate has a movable section 13 inadvance of the line 'followed by the stitch and a shield 111 extendsdownwardly from that section around the working parts beneath the plate.A link 15 is pivoted to the two parts of the workplate at an angle and aing movement.

f guide 16 is secured to the under sur- K. .Horn

face of the iixed part of the plate at the rear edge. A projecting plate17 is secured to .the under surface of the movable part on the oppositeside and it enters asockct 18 on the xedpart. mits the forward part 'ofthe work plate'to be moved out of the way so as to give access to therota-ry hook and other mechanism below the plate, andthse features aremade the subject of a separate application.

The bobbin holder 19 has a bearing r'im fitting within a bearing groovein the revolving hook ring 3, and it is provided with a hook `20 nearthe top and facing the top for the purpose of engaging and spreading tobe p aced within the holder with its' axis parallel t0 the axis of ,thebearing rim but notconcentric therewith being eccentric on the sideopposite to that on which the hook is placed. The bobbin passes throughan opening on one lside of the holder over a column or post whichcarries a member 22 longitudinally movable therein which has fitted toits end 'the retaining arm 23. This retaining arm extends out to theedge of the bobbin and is curved down over the edge within vthe marginof the holder and it serves the double purpose of holding the bobbin inplace'and offering some resistance to its turnin movement, thus placingten- "sion on theA t read drawn from the bobbin. 4Thesefeatures are alsomade the subject of a separate application. The present inventionrelates to the means for retaining the holder against rotation and thatmeans includes an arm 2e ri idly secured to some Ypart of the frame o'the machine and having its end 25 extending downwardly into the pathof-a portion of the holder so as to prevent any material turn- In theparticular form shown the arm 24 has its end curved and extends veryslightly within a depression or opening 26 in the face of lthe holderimmediately behind the hook 20 and in the upper part of the holder. Thedepression or opening 26 is wider than the end 25 of the arm 24andtherefore when the arm occupies a position in the center of theopening a loop of thread may easily and freely pass down between the endand the holder without meeting any resistance.

This construction per" the loo of thread. A bobbin 21 is adapted.

On the side of the holder opposite the" arm- 24 I make'use rock so as tobring the finger 27 into and out of contact with the projection 28. Whenthe finger 27 is in contact with the projec tion as shown in Fig. 2 theholder is moved or rotated slightly in the reverse direction.

to the movement which the rotary hook tends to give to it and it ismoved only to such an extent as to bring the end 25 of arm 24 into thecenter part of the opening or depression out of contact with any part ofthe holder. When the finger 27 is in contact with the projection 28-itwill prevent any turning under the influence of the rotary hook and thusthe end 25 of arm 24 is held out of contact with the walls of theopening into which it projects. The operation of the arm 29 is timedthat the finger 27 will engage the holder as the loop is b'eing carrieddown by the hook 31 toward the arm 24, and therefore the loop can passfreely beneath it. After the loop passes the end the arm 29 moves backcarrying the finger 27 out of Contact with the projection 28 and thusthe loop can ride up the inclined surface of the projection 28 andpasses the end of the finger 27 freely. The end surface of'the finger 27being upwardly inclined avoids the possibility of catching the threadand this inclined arrangement is utilized to engage and depress theprojection 28 turning the holder as above described. In order to guardagainst an accidental engagement of the loop with the arm 24 Ipreferably secure to it a guide 32 which extends upwardly toward thehook 20 so as to guide the loop down to the point of the arm 24.

It will be understood that in its broader aspects my inventionl is notlimited to the particular means for causing the slight relative movementbetween the retaining arm 24 and the bobbin holder so as to permit theloop to pass freely between them and is furthermore not limited to theparticular means for operating the finger 27. I have shown the finger 27operated from the same shaft which operates the feed mechanism. v

As shown in the drawings the feed member 33 is pivoted at one end to anarm 34 carried on the rock shaft 35 and the rock shaft 35 is Igiven anoscillating movement by means of the link arm 36 which is given alongitudinal movement by the means shown in Fig. 5. That means'constitutes the subject of another application but it in` cludes asliding block 37 guided by the parallel arms 38 on the end of the linkarm 36 and an eccentric 39 worksin that slide block and is secured tothe shaft 6. A link arm 40 is pivotally connected to the linkl arm 36between its ends and extends there from at an angle being pivotallyconnected at its other end to the bell crank 41. The bell crank can beturned by a thumb screw 42 to different positions along the slot 43 -soas to vary the angle of the link arm 40 tothe link arm 36 and to therebyvary the amount of movement imparted to the shaft 35and consequently thelength of the longitudinal movement of the feed bar 33. The feed bar isgiven its up and down movement by the rock shaft 44 which is oscillatedby the link 45 operated by the eccentric 46 on shaft 6. There is a linkconnection between an arm on shaft 44 and the end of the feed member 33consisting of the rod 47 having ball and socket connections at its endsand the spring 48. v

The rocking arm 29 is operated from the rock shaft 44 which gives the upand down movement to the feed bar by means of an arm 49 and a link 50`and since the shaft 4 4 makes only one oscillating movement during tworevolutions of the revolving hook it will be observed that the finger 27will be brought into engagement with 'the holder but once during tworevolutions of the hook and as above stated this action is so timed thatit' will occur just as the hook is carrying the loop of thread downtoward the arm 24.

I-Iavi'ng thus described my invention, what I claim is:

1. In a revolving hook sewing machine, the combination with a bobbinholder, of a rotary hook for passing a loop of thread around saidholder, a fixed arm projecting slightly into an opening in the face ofsaid holder. on one side to prevent its rotation and a rocking arm onthe opposite side o said Holder below the top for engaging said holderon its inward movement Vto turn it sufficiently to bring` it inte aposition where the fixed arm will be out of Contact with the walls ofsaid opening in said holderand means for operating said rocking arm ateach alternate revolution of the rotary hook.

2. In va sewing machine, the combination with a bobbin holder having a.hook for spreading a loop of thread and an opening in the upper part ofits face behind said hook, of a revolving hook for passing said looparound said holder, a fixed arm having a downwardly inclined endprojecting slightly into said opening to prevent the rotation ofsaidholder, and means for moving said holder to such an extent that saidarm will be out of contact with the walls of said opening in said holderwhen said loop approaches said arm thus allowing a free passage of theloop beneath said arm.

3. In a sewing machine, the combination witha bobbin holder having ahook for spreading a loop of; thread and an opening in the upper part ofits face behind said hook, of a revolving hook for passing saidv looparound said holder, a fixed arm having a downwardly. inclined fendprojecting slightlyinto-said opening to .prevent the ro tation ofs:iid.hol der, and a movable finger having an upwardly inclined undersurface adapted to` engage theupper portion of said Iholder :on 4theside vopposite', to said fixed arm and below. the top to move. itslightly, and means for. operating said movable. finger." u

v 4. In a sewingv machine, the combination with a b obbin holder havinga:hook 'for .spreadinga loop of thread and an opening in the upperpartof its face behind said" hook, of a revolving hook for passingsaidloop around said holder, a fixed arm having a downwardly inclined'. endprojecting slightly into said opening to preventthefrotation of saidholder a projection on the upper portion of the holder on the sideoposite to said opening having 'anupwardly inclined lower surface, amovable finger' having an upwardly inclined lower surface adaptedtoengage the. upper end'of said projection to move said holderslightly,and

' means for operating said movable finger.

5. In a sewing machine, the combination with a bobbin holder having ahook for spreading' a loop ofthread 'and an opening in the upper part ofits face behind said hook, of a revolving hook for passing said looparound said'holder, a fixed'arm having a downwardly inclinedA endprojecting slightly into said opening to prevent the rotation of saidholder, a projection on the upper portion of the holder on the side'opposite to said opening havin an upwardly' inclined lower surface, 'aroc ing arm piv'- oted at its lower' end and oarrylng a laterallyprojecting finger at' its upper end having an upwardly inclined lowersurface a'daptedto engage the top of said projection,

and means 4for rockingsaid' arm.

6. Ina sewing machine, the combination" wlth a bobbni holder having ayhook vforspreading aloop of thread and an opening in the upper part ofits face behindsaidhook, ofi' a revolving hook for passing said looparound said holder, a fixed arml having a downwardly inclined endproject-ing slight-ly into said opening to prevent the-rotation of saidholder, means-` vfor `moving said holder to such an extent that-saidarm. will be out of contact with the Walls of said point of saida'ifinf-4 opening I said. holder "when said apguide extendingupwardlyjfrom said fixed larm for. directingthe 'loop-.off thread to thesaid .plate and adapted to pass a loop of thread aroundit, aclothfeeding member, t

means forreciprocating said member, means for. raising andylowering-said member at.

vthe combination 'with' a 'needle 'and needle bperating mechanisin'gofgafc'loth plate, a-b'obbinholder and a:

yrevolving" hoolrcarrying said holder below venting 4any substantial:rotation ofsaid Awith a needle and needle.oper'ating mechanism, of acloth plate, a bobbin holder and a `revolving hook carrying said holderbelow holder while permitting the free passage of said plate and adaptedtopass a loop of thread around "it,a cloth feeding member, means forreciprocating said member, means for raising and lowering said member ateach alternate revolution .of said revolving hook including a rockshaft, means for preventing any substantial rotation of said holderwhile permitting tlie free passage of the loop around it including anupwardly ex'- tended arm pivoted at its lower end carrying a finger atits upper end for engaging' said holder, and link connections betweensaid arm and roel; shaft for operating said fingerto engage anddisengage said holder. 9. 'In a' revolving hook se\ \'ing"mac1iine, thecombination with a bobbiri holder, of a rotary hook for passing a loopof thread around said holder, cloth 4feeding inecli'anism, an armVhaving its' end in the patlrof s aid holder to 'prevent rotation, a4movable. arm adapted.to engage said holder on the opposite .side torotate it slightly out of contact with said first mentioned arm andmeans for operating said movable arni'from said feed operating mechanismat leach alternate revolution of the hook.

In testimony whereof I affix my signature in presence-4o' twowitnesses.

i' RICHARD K. H OHMANN. Witnessesz

